Helical Spin Texture and Interference of Majorana Bound States in One-Dimensional Topological Superconductor
Helical Spin Texture and Interference of Majorana Bound States in One-Dimensional Topological Superconductor
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DOI：
10.7566/jpsj.85.013701
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发表时间：
2015-11
影响因子：
1.7
通讯作者：
T. Kawakami;X. Hu
中科院分区：
文献类型：
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作者：
T. Kawakami;X. Hu
研究了在超导衬底和两个铁磁绝缘体（FI）的异质结构中，二维量子自旋霍尔绝缘体的螺旋边态实现的一维Majorana束缚态（MBSs）.利用Bogoliubov-de Gennes方法证明了在MBS波函数中存在螺旋自旋织构，其螺距与费米动量成正比。此外，在靠近一个FI边缘的位置和两个FI之间的中点处，通过扫描隧道显微镜和光谱学同时检测局域态密度，不仅可以绘制出能谱±E cos（λ/2），其中λ是两个FI的磁化之间的相对角度，而且实验上证明了两种准粒子激发不会相互混合，因为受到与MBS相关的宇称守恒的保护。
We investigate one-dimensional (1D) Majorana bound states (MBSs) realized in terms of the helical edge states of a 2D quantum spin-Hall insulator in a heterostructure with a superconducting substrate and two ferromagnetic insulators (FIs). By means of Bogoliubov–de Gennes approach we demonstrate that there is a helical spin texture in the MBS wave function with a pitch proportional to the Fermi momentum. Moreover, simultaneous detection on local density of states by scanning tunneling microscopy and spectroscopy at a position close to one FI edge and at the midpoint between the two FIs can not only map out the energy spectrum ±E cos(ϕ/2) where ϕ is the relative angle between the magnetizations of two FIs, but also prove experimentally that the two quasiparticle excitations do not mix with each other as protected by the parity conservation associated with the MBSs.